Keyboard



FIG. 1 is a top view of a keyboard according to our new design;

FIG. 2 is a bottom view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a front view thereof; and,

FIG. 6 is a rear view thereof.

The broken lines shown in the figures are for environmental purposes only and form no part of the claimed design. 

CLAIM The ornamental design for a keyboard, as shown and described. 